Simplify the following expression: $r = \dfrac{7}{4z} + \dfrac{3}{4z}$
Answer: Since the expressions have the same denominator we simply combine the numerators: $r = \dfrac{7 + 3}{4z}$ Combine like terms: $r = \dfrac{10}{4z}$ Simplify by dividing numerator and denominator by 2: $r = \dfrac{5}{2z}$